How do we know our reasoning is valid?

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UhOH
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How do we know our reasoning is valid?

Post by UhOH » Wed Jan 06, 2016 11:58 pm

Recently I have been wracked by global scepticism, are we brains in vats, were the world and all our memories created last Thursday etc. I found that with the use of certain logical tools like Ockham's razor and abductive reasoning that I could dispel some of these sceptical doubts. But how do I know that my reasoning is true? How do I know that there isn't, say, a 100% probability that we are brains in vats? Couldn't I expand this to be more general as well, how do I know whether my deductive reasoning is valid? How do I know if any of my reasoning is true at all?

Impenitent
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Re: How do we know our reasoning is valid?

Post by Impenitent » Thu Jan 07, 2016 10:34 am

circularly

-Imp

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Hobbes' Choice
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Re: How do we know our reasoning is valid?

Post by Hobbes' Choice » Thu Jan 07, 2016 12:02 pm

UhOH wrote:Recently I have been wracked by global scepticism, are we brains in vats, were the world and all our memories created last Thursday etc. I found that with the use of certain logical tools like Ockham's razor and abductive reasoning that I could dispel some of these sceptical doubts. But how do I know that my reasoning is true? How do I know that there isn't, say, a 100% probability that we are brains in vats? Couldn't I expand this to be more general as well, how do I know whether my deductive reasoning is valid? How do I know if any of my reasoning is true at all?
The brain in a vat suggestion is pure fantasy. We all know that.
Why a brain? Why not do without matter altogether. It's obviously a confused idea, which on the one hand denies the material world whilst confirming it.
A brain is a vat cannot work. It would not make any sense.

I found the Matrix film quite promising, until they gave their raison d'etre for keeping people in this state. The black guy held up a battery and said for "energy", - well what a crock of shit. It ruined the film for me. It would be pointless keeping people hooked up for their energy as we all know that energy cannot be created or destroyed and it would cost more energy to keep them suspended that you could get out of the system. Such a thoughtless explanation by the film makers destroyed my suspension of disbelief that is necessary for such a film to remain credible.
For a suggestion to be probably, it has to be credible.
1) no known science could make the BinV hypothesis possible.
2) no system could deal with the variables necessary to make it work.
3) Since the information in the system would have to included the entire universe, made available to your brain, you might as well just let your brain walk about in the universe. It would be easier.

Aside from the obviously silly point. Your deductive reasoning is circular and so cannot be invalid as the meaning of the words contained in any deductive system fully predict the outcome. Deduction is the same as definition.

If you want to talk about induction then go ahead. Before then, run along and first understand what the difference is.

uwot
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Re: How do we know our reasoning is valid?

Post by uwot » Thu Jan 07, 2016 5:17 pm

I'd stick to abduction. It's not foolproof, but it's the best we have. Just arm yourself with as many facts as your head can handle.

Dalek Prime
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Re: How do we know our reasoning is valid?

Post by Dalek Prime » Fri Jan 08, 2016 7:45 pm

UhOH wrote:Recently I have been wracked by global scepticism, are we brains in vats, were the world and all our memories created last Thursday etc. I found that with the use of certain logical tools like Ockham's razor and abductive reasoning that I could dispel some of these sceptical doubts. But how do I know that my reasoning is true? How do I know that there isn't, say, a 100% probability that we are brains in vats? Couldn't I expand this to be more general as well, how do I know whether my deductive reasoning is valid? How do I know if any of my reasoning is true at all?
Recognizing your consciousness is the first step. You build from there.

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A_Seagull
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Re: How do we know our reasoning is valid?

Post by A_Seagull » Sat Jan 09, 2016 10:35 pm

UhOH wrote:. But how do I know that my reasoning is true? How do I know that there isn't, say, a 100% probability that we are brains in vats? Couldn't I expand this to be more general as well, how do I know whether my deductive reasoning is valid? How do I know if any of my reasoning is true at all?
The facts of the world constitute a model that is used for interaction with the world.

Reasoning is much the same; it's a hypothesised method of making inferences about the world.

Certainty is not a necessary requirement for interacting with the world. In fact certainty is nothing more than a label that one might attach to a fact or method of reasoning.

Skip
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Re: How do we know our reasoning is valid?

Post by Skip » Sat Jan 09, 2016 10:48 pm

UhOH wrote:Recently I have been wracked by global scepticism, are we brains in vats, were the world and all our memories created last Thursday etc. I found that with the use of certain logical tools like Ockham's razor and abductive reasoning that I could dispel some of these sceptical doubts. But how do I know that my reasoning is true? How do I know that there isn't, say, a 100% probability that we are brains in vats? Couldn't I expand this to be more general as well, how do I know whether my deductive reasoning is valid? How do I know if any of my reasoning is true at all?
What do you need to know?
Why do you need to know it?

How you go about finding out depends on those two answers.

If you are indeed a brain in a vat, living a made-for-you fantasy, there must be caretakers: one or more intelligent beings able to keep you alive and functioning in that state. Who and what they are, you cannot know unless they communicate with you. If they do, you'll never be able to find out whether they're telling the truth, or even whether the communication you receive is from them or is merely part of your make-believe world experience. If they do not communicate, you will never be able to find out that you are in a vat, that you are a brain, whether such a hypothetical brain was removed from a physical entity or grown from stem cells, and what its origins might have been. You cannot know that you have any physical existence at all: you might be a figment or simulacrum.

So, you have a choice:
Accept and explore the world as you find it.
Make up - or adopts - a story that suits your temperament and keep colouring it to give your life "meaning".
Braid yourself into a mental basket of questions without answers.

Dubious
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Re: How do we know our reasoning is valid?

Post by Dubious » Wed Jan 13, 2016 5:21 am

Feedback, what or if any, whether your brain goes through the washing & drying cycle or not.

wirius
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Re: How do we know our reasoning is valid?

Post by wirius » Fri Jun 17, 2016 12:04 am

I would argue that the "Brain in a vat argument" is an induction. We can conclude that our logical deductions trump any inductions we can make. I show how we can define and separate deductions from inductions in post "Subjective Deduction part 1". Unless of course I'm wrong. =P

ken
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Re: How do we know our reasoning is valid?

Post by ken » Thu Jul 14, 2016 6:53 pm

How we know our reasoning is valid is when we know, for sure,that not just every person but everything could agree.

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Hobbes' Choice
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Re: How do we know our reasoning is valid?

Post by Hobbes' Choice » Thu Jul 14, 2016 7:58 pm

wirius wrote:I would argue that the "Brain in a vat argument" is an induction. We can conclude that our logical deductions trump any inductions we can make. I show how we can define and separate deductions from inductions in post "Subjective Deduction part 1". Unless of course I'm wrong. =P
I think you need to lighten up on the deduction/induction thing. All knoweldge and thinking requires both and a lot more besides.
Deductions don't trump shit.
"unless you are wrong". think about this.
Start here!
A brain in a vat argument is not an induction.

wirius
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Re: How do we know our reasoning is valid?

Post by wirius » Thu Jul 14, 2016 11:56 pm

Hobbes' Choice wrote:
I think you need to lighten up on the deduction/induction thing. All knoweldge and thinking requires both and a lot more besides.
Deductions don't trump shit.
"unless you are wrong". think about this.
Start here!
A brain in a vat argument is not an induction.
Of course I always leave the possibility open that I am wrong. But for that possibility to become a reality, it must be shown that I am wrong. I'm a little dissapointed that when I pointed out you were using a straw man fallacy against me, you did not seek to understand what I was stating, or adequately counter the points I made, and stubbornly stuck to your beliefs. You would have found that the end conclusion to my paper determined knowledge required a deductive basis to start, but from that deductive basis we could build a way to rationally evaluate inductions, and use those in rational evaluations of our beliefs. And yes, from this it can rationally be determined that the "Brain in a Vat" argument is an induction, and does not need to be logically evaluated when there are better inductions, and even deductions, that counter the brain in a vat argument.

But ultimately, I don't think you really ever understood what I was writing. That's ok, it was new and complicated. Its a lot easier to stick to the biases and beliefs we already have and get angry when people challenge them.

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Hobbes' Choice
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Re: How do we know our reasoning is valid?

Post by Hobbes' Choice » Fri Jul 15, 2016 12:33 am

wirius wrote:
Hobbes' Choice wrote:
I think you need to lighten up on the deduction/induction thing. All knoweldge and thinking requires both and a lot more besides.
Deductions don't trump shit.
"unless you are wrong". think about this.
Start here!
A brain in a vat argument is not an induction.
Of course I always leave the possibility open that I am wrong. But for that possibility to become a reality, it must be shown that I am wrong.... And yes, from this it can rationally be determined that the "Brain in a Vat" argument is an induction, and does not need to be logically evaluated when there are better inductions, and even deductions, that counter the brain in a vat argument..
Please state HOW this is an induction!
Repeating the assertion does not make it more truthful.

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Greta
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Re: How do we know our reasoning is valid?

Post by Greta » Fri Jul 15, 2016 2:23 am

Relativity says that we can't know whether our reasoning is ultimately valid, only relatively so. We can't be sure of the reality of our foundation ideas. Dalek's idea of starting with your own consciousness makes sense, although that may be a perspective error.

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Hobbes' Choice
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Re: How do we know our reasoning is valid?

Post by Hobbes' Choice » Fri Jul 15, 2016 9:38 am

Greta wrote:Relativity says that we can't know whether our reasoning is ultimately valid, only relatively so. We can't be sure of the reality of our foundation ideas. Dalek's idea of starting with your own consciousness makes sense, although that may be a perspective error.
Actually all analytical reasoning is fully self validated. For example because 1+1=2, 1-2=1 is 100% valid.
The trick is to not let yourself be drawn into a position that this says anything about the reality or the world around you.

You can use this to model reality. For example If I have two oranges and give one away I shall have one orange. However no orange is the same as any other and so this does not verify the analytical assumption.

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